The present invention relates generally to a device capable of smoothing and/or polishing various materials. Smoothing includes grinding, stock removal, honing, polishing, sanding and similar actions of flat and curved surfaces to polish and/or smooth such surfaces. Abrasives are used to cut and polish surface areas of materials, including stone, ceramic, engineered stone, concrete, metal, glass, wood, composite materials and combinations of one or more of the foregoing, by way of example and not limitation.
Polishing and smoothing devices are well known in the art. Various devices have been suggested that include a main body and a head or plurality of heads rotating in the direction of the contact surface and that utilize an abrasive surface. For example, U.S. Pat. No. 7,022,004 to Böhler, the subject matter of which is herein incorporated by reference in its entirety, describes a device utilizing three tool holding fixtures driven by a central motor and a set of gears in a triangular system for rotation around their own rotational access such that the tool holding fixtures are rotatably mounted at least around a rotating axis serving as a work axis and each of the tool holding fixtures requires a driving means for rotating each of the tool holding fixtures. Another polishing device is described in U.S. Pat. No. 7,427,228 to Kirsch, the subject matter of which is herein incorporated by reference in its entirety, which is a handheld material conditioner including at least three orbital head assemblies.
However, all of these orbital polishing devices use rotating polishing heads that are mounted to a plate and the plurality of polishing heads are simultaneously driven by an attached or external motor which powers a spindle or shaft in combination with a series of gears and/or belts to rotate the plurality of orbital polishing heads at the same speed in the same direction. These polishing heads force the rotational direction of the abrasive pad to any contact area and all of the polishing heads are driven by the mechanical means to simultaneously rotate the polishing heads without any independent motion.
One of the problems associated with these orbital polishing devices is that when substrates to be smoothed or polished have surfaces that are curved or uneven, the simultaneous motion of all the orbital polishing heads can cause these uneven and curved portions to be flattened and/or rounded over. In addition, by using mechanical force such as gears and/or belts, the abrasive polishing pad can produce an uneven surface on the material to be polished, resulting in imperfections.
It would be desirable to provide an orbital smoothing and/or polishing device in which each of the plurality of polishing heads is capable of independent rotation. It would also be desirable to provide a device that is capable of self-leveling on uneven surfaces so that such surfaces can be more evenly polished.
In addition, these orbital polishing devices can be used as a single device hooked up to a motor (i.e., a “handheld” device) or alternatively, can be used in slab polishing machine. Slab polishing machines are used for polishing materials such as stone slabs and other like materials and multiple orbital polishing devices are mounted to smooth or polish the entire width of the slab simultaneously.
One of the problems with using these orbital polishing devices in a slab polishing machine is that the polishing assemblies can become worn out and the gears and belts can break. If this happens, the slab polishing machine must be taken off line so that the orbital polishing device can be taken apart and rebuilt. Thus, it would be desirable to provide an orbital polishing device for use in a slab polishing machine that can be more easily repaired and replaced.